public class AmericanPeople extends People {
    //重写public void speakHello()方法，输出"How do you do"
    public void speakHello() {
        System.out.println("How do you do");
    }
    //重写public void averageHeight()方法，输出"American's average height:176 cm"
    public void averageHeight(){
        height = 176;
        System.out.println("American's average height:" + height +" cm");
    }
    public void averageWeight() {
        weight = 75;
        System.out.println("American's average weight:"+weight+" kg");
    }
    public void americanBoxing() {
        System.out.println("直拳、钩拳、组合拳");
    }
}